Principate Timeline | Principate Basics
The principate is the name we give to mark the period in ancient Roman history when one man (the princeps) took political control. The period of the principate runs from Augustus to Diocletian, who split the Roman Empire into four parts, the tetrarchy. The earlier period, the Republic, is seen as a time of greater freedom than the principate, but the principate initially brought peace from civil war.
Sometimes the term principate is used to cover the period from Augustus to the Fall of Rome in A.D. 476.